This proposal's long-term goal is to develop radiographic phantoms to address the following critical needs in the emerging field of digital x- ray imaging: quality control procedures for daily operations; quality assurance methods for users to evaluate products, perform acceptance testing and determine optimum system operating parameters; development tools for manufacturers to test new hardware and software products. Because neonatal chest radiography is technically challenging and has profound radiation dose implications, it was selected as the focal point for phantom development. The phantom will contain test objects for objective and subjective measurement of system performance. Phase 1 of this project includes these Specific Aims: 1) Establish parameters that define the neonatal chest phantom; 2) Construct prototype phantoms based on the above parameters; 3) Evaluate the suitability of prototype phantoms for clinical tasks. Successful phantom design will be determined by the appearance and histogram analysis of images; the attenuation values of anatomic structures; and the diagnostic performances of radiologists with detection of test objects within the phantom. The clinical significance of this phantom is that it could be used to assure optimal performance of equipment and minimize x-ray exposure and the concomitant risk of induced malignancy to neonates. PROPOSED COMMERCIAL APPLICATIONS: A new class of x-ray phantoms will be developed for use with computed radiography and other digital x-ray imaging devices. The phantom will be used in quality assurance programs, as a design tool for equipment vendors, and as a research tool for reducing radiation exposure while maintain image quality. This Phase 1 feasibility proposal will initially develop a neonatal chest phantom as it tests the limits of computed radiography. The worldwide market for this phantom is estimated to be $27,000,000 to $37,000,000 over the next five to seven years for the pediatric phantom alone. With the extension to a new class of digital x-ray imaging phantoms, the potential market should exceed $150,000,000.